Browse Prior Art Database

TECHNIQUE FOR PLAN-VIEW LAYER-SPECIFIC TEM SPECIMEN-PREPARATION

IP.com Disclosure Number: IPCOM000006498D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-09
Document File: 2 page(s) / 102K

Publishing Venue

Motorola

Related People

N. David Theodore: AUTHOR [+2]

Abstract

Transmission electron microscopy ITEM] is an ana- lytical technique that involves propagation of electron beams through a thin foil of material. The transmitted beams contain information that make possible the anal- ysis and study of(i) microstructure of device-structures, semiconductor, metal, or insulating layers, (ii) continu- ity of layers, including the presence of pin-holes or islanding, (iii) quality of interfaces, (iv) material interac- tions such as phase-reactions, corrosion, action of diffi- sion barriers and glue layers in device-structures, (v) defects such as dislocations, grain-boundaries, twins, pre- cipitates, stacking faults in materials. For plan-view TEM [REM) analysis, thin-foil specimens (-10-500 nm thick) have to be prepared in plan-view, from the materials of interest; the resulting foils have to be electron transparent.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Page 1 of 2

MOTOROLA INC. Technical Developments Volume 16 August 1992

TECHNIQUE FOR PLAN-VIEW LAYER-SPECIFIC TEM SPECIMEN-PREPARATION

by N. David Theodore and Ray Doyle

  Transmission electron microscopy ITEM] is an ana- lytical technique that involves propagation of electron beams through a thin foil of material. The transmitted beams contain information that make possible the anal- ysis and study of(i) microstructure of device-structures, semiconductor, metal, or insulating layers, (ii) continu- ity of layers, including the presence of pin-holes or islanding, (iii) quality of interfaces, (iv) material interac- tions such as phase-reactions, corrosion, action of diffi- sion barriers and glue layers in device-structures, (v) defects such as dislocations, grain-boundaries, twins, pre- cipitates, stacking faults in materials. For plan-view TEM [REM) analysis, thin-foil specimens (-10-500 nm thick) have to be prepared in plan-view, from the materials of interest; the resulting foils have to be electron transparent.

  Conventional techniques (of plan-view TEM speci- men preparation) are designed for analyzing bulk mate- rial, or single layers deposited on top of a substrate. This paper presents a novel technique for preparation of plan- view TEM specimens of buried-layers in multi-layer semi- conductor structures. The technique makes analysis of specific buried layers possible.

  The conventional technique for preparation of plan- view TEM specimens is as follows. First, ultrasonically drill a 3mm disc from the wafer, with the layer-of-interest [LOI) on top. Dimple the disc from the bottom to obtain a final thickness [in the center) of - 10vm. Ion mill the disc from rhe borrow till a perforation is obtained. The perforated disc is shown in perspective-view in Figure la and in cross-section in Figure lb. Material near the perforation in the disc will be electron-transparent, and ready for TEM analysis. The problem with this tech-

nique is th...